A flooring element (1) according to the invention comprises: a) a panel element (2); b) second fastening means (64, 604); c) first fastening means (44, 404). The first fastening means include a coupling groove (44) extending in a first assembling direction (X). The second fastening means (64, 604) are arranged to fasten together the second fastening side (6) of the flooring element (1) and a fastening side of another similar flooring element of the modular floor, thereby preventing relative displacement of the two flooring elements at least in the first assembling direction (X). This enables building modular floors which are considerably resistant to tangential stresses applied to the walking plane in all directions parallel to the walking plane itself. According to the present invention, modular floors for gyms, sports courts and exhibition stands can therefore be built.